There is still a debate that a significant number of parliamentarians want to have about religious freedoms and conscientious objections. Many MPs and senators from all political persuasions will want to have a say.

After all, this is free vote.

Scores of amendments are expected to be put up and will likely be voted on, although not all. Whether any, some or all amendments are accepted is a another question entirely.

Debate on the bill in the Senate is now underway.

But according to the Finance Minister Mathias Cormann, who led the successful postal survey, debate on amendments will only start in the week of November 27.

He's promised that the Senate won't be done for 2017 until the marriage amendment bill is done.

"That whole week, that whole sitting, that whole first sitting week of the final sitting fortnight, has been earmarked for debate in the Senate," Cormann told 730 on Wednesday.

"Extended sitting hours on the Tuesday. And if the consideration of the legislation hasn't been finalised by the end of Thursday the 30th of November then we will continue to sit until it is finally dealt with."

The bill then has to go to the House where senior Government members are not expected to have patience for serious delays.

The Dean Smith bill also crucially has Labor's support and Opposition leader Bill Shorten is not keen on significant changes.

"The Smith bill was the result of a cross-party parliamentary committee," Shorten told 730 on Wednesday.

"In other words, this bill is already a compromise bill to amend the Marriage Act to allow same-sex marriage.

"I don't see the case is made for massive amendments. There might be one or two technical matters which, if people make the point well, then we need to clarify."

"I believe it will be passed by the House of Representatives not later than the 7th of December, perhaps a few days sooner than that and then commencement of the bill will not be delayed," Attorney-General George Brandis told the ABC on Thursday.

He's talking here about the technical process for a bill, passed in the Lower House of Parliament, becoming law. It is often not immediate.

"I think the beginning of the year is what we are looking at," the Attorney-General said.

So it's likely the legislation will pass before Christmas, but weddings? Perhaps not Christmas nor New Years Eve. Likely soon after, but it is all in the hands of our representatives in Canberra.